Hithertofore, organic phosphoric and carbamate insecticides and so on are conventionally applied for harmful lawn grass insects. These insecticides involve problems such as an adverse effect on the environment due to their toxicities and the induction of resistance of the insects, their complicated procedures and harmness to the health of workers handling them. Particularly, with the recent demands for the reduction or non-use of agricultural chemicals on golf course turfs, the control and elimination of harmful lawn grass insects is becoming increasingly difficult. In addition, most of the major species of harmful lawn grass insects are nocturnal and thus their elimination is preferably conducted during their active period at night. However, no satisfactory method therefor has been found.
Accordingly, to solve such problems, a method has been demanded for controlling and eliminating insects with a good working efficiency, highly safety and non-pollution under a variety of complex conditions of location, climate and insect growth in various lawn areas.
On the other hand, an agricultural application of a stable, biodegradable foam using a solid surfactant has been proposed in JP-A-3-81203 (the term "JP-A" as used herein means "unexamined published Japanese Patent Application"). However, it mainly relates to the promotion of seed germination or field markers for the spraying of herbicides, pesticides, and the like. Further, a method in which agricultural chemicals such as insecticides and bactericides are sprayed in the form of foam has been proposed in JP-B-4-57296 (the term "JP-B" as used herein means "examined Japanese Patent Publication"). Thus, both methods only relate to the use of insecticides, bactericides and the like, and therefore they are simply variations of methods of distribution of agricultural chemicals.